Doctor for paper-making machinery



Feb. 6, 1934. F. w. VICKERY 1,945,761

DOCTOR FOR PAPER MAKING MACHINERY Original Filed May 3, 1930 //YVENTOR A T TOR/v5- Y.

Patented Feb. 6, 1934 UNiTED STATES PATENT OFFICE BOC'I'OR FOR PAPER-MAKING MACHINERY Frederick William Vickery, London, England, as-

signor to Vickery Incorporated, a corporation of Massachusetts 1930 '7 Claims.

In my co-pending application Serial No. 449,442 filed May 3, 1930, from which this present application is divided and on which Patent No. 1,883,167 was granted October 18, 1932, I have described doctors for the rolls of paper-making machines which enable the doctoring edge of the blade to be set at a large angle to the roll, say from 45 to nearly radial, while the blade is so supported that it can adapt itself to the roll and the risks of chattering and of damage to the roll to which the steep setting of the blade might give rise are obviated. My said application also described further purposes which are achieved by the constructions therein claimed.

As stated in my above-mentioned patent the purposes and advantages there mentioned and above referred to may be in large part achieved by a comparatively simple construction of doctor employing a thin blade of curved cross-section.

It is to this construction of doctor that the present application relates.

The doctor is shown in diagrammatic end elevation in the accompanying drawing.

The stiff carrier 1 extending across the papermaking machine swings on pivots 2, and is pressed towards the roll 3 either by springs or by its own or additional weight. The doctor blade is attached to the carrier in the usual way, and for that purpose its rear edge 4 is made flat.

It is made as usual of thin sheet steel or other resilient metal, but is bent in its width so that the plane of one edge is inclined to that of the other at an angle which may be as much as 90. The curvature may be gradual and extend over the whole or the greater part of the width of the blade. But preferably the part next the doctoring edge is straight or so curved that the angle of contact with the roll varies but little as the blade wears. The form requisite for this purpose will depend on the path along which the doctor is moved towards the roll to take up wear. In the form illustrated, where the doctor carrier 1 is pivoted and turns on an axis passing through the roll, the working edge and as much more of the blade as can be allowed to wear away before renewal is necessary is slightly curved, so as, when the blade is in position, to form a cylindrical surface 5 co-axial with the pivots 2. The working edge of the blade preferably stands at a large angle to the roll as indicated. Hence between the cylindrical part 5 and the flat rear edge 4 the blade is curved more or less sharply through something like a right angle, as indicated at 6.

I claim:

1. A doctor for the rolls of paper-making machines comprising a carrier and a resilient blade extending the axial length of the roll secured at one edge to said carrier and having its other edge applied to the roll, said blade being curved in cross section so that at the edge bearing upon the roll it stands at a larger angle to the tangent plane to the roll at the line of contact with the blade than does the part secured to the carrier.

2. A doctor for the rolls of paper-making machines comprising a pivoted rigid carrier, and a resilient blade extending the axial length of the roll, said blade having a fiat edge clamped upon said carrier and a consumable part curved approximately to a cylindrical surface coaxial with the pivots of the carrier.

3. A doctor blade for the rolls of paper-making machines consisting of a thin strip of sheet metal extending the axial length of the roll and having in cross section a fiat part for attachment to a carrier a slightly curved consumable part next the doctoring edge of the blade, and a sharply curved part between the flat part and the slightly curved part.

4. Scraper blade for cleaning paper drying drums, and the like, comprising a substantially straight body portion adapted to be rigidly secured in a fixed position, and downwardly curved portion adapted to bear with its entire edge face against the drum surface to be cleaned, the contacting edge face being radially disposed relative to the drum surface and of a length substantially equal to the cross-section of the blade.

5. A doctor blade for cleaning paper drying drums and the like, comprising a substantially straight body portion adapted to be rigidly secured, and a downwardly curved portion adapted to bear against the drum surface to be cleaned throughout its length.

6. A scraper blade for cleaning paper drying drums and the like, comprising a substantially straight body portion adapted to be rigidly secured in a fixed position, and downwardly curved portion adapted to bear with its entire edge face in a substantially radial direction against the drum surface to be cleaned, the contact edge face being of a length substantially equal to the cross-section of the blade.

7. A doctor blade for cleaning paper drying drums and the like, comprising a substantially 5 straight body portion adapted to be rigidly secured, and a downwardly curved portion adapted 

